Theorem and Corollary
by sagredo
Summary: A series of Moriarty-related one shots, investigating, amongst other theories, the idea that the Professor and Holmes were mentor and protege prior to being enemies. Except for Ch. 4, which examines a different idea entirely.
1. Grief

The skeleton had been laid out piece by piece on the slab before us, arranged as it would have been when muscle, tendon, and sinew had held it together to form a body. It was not quite complete, but the major bones had been accounted for, so that only a vertebra here or carpal bone there stood out as missing to my medically trained eye. It was clear that it had spent much time in water - for even after they had been cleaned, the bones retained a sickly greenish-gray hue. It was almost difficult to believe, as we clustered around the table in the morgue, that we may have been looking at the earthly remains of Professor Moriarty.

Inspector Lestrade stood at some distance with his hands behind his back, watching Holmes expectantly as he circled the table, inspecting the remains from different angles.

I watched Holmes as well, though with some measure of concern.

He seemed to me to be giving the matter before him much more thought than it was due. His eyes were a pair of grey storm clouds, narrowed in consideration, his lips pursed and his features keen in thought. He had taken on that fierce, bird of prey look he could at times when faced with a puzzle which provided a true challenge. Could it be, I wondered, that he had seen something about the bones which suggested such a conundrum? To me it seemed that there was far too little to be had from them for this to be true. What else, then, could have roused this hunting hound side of his character so?

At length he paused, passing a hand over his mouth thoughtfully.

"Well, the age is right," he told Lestrade.

"Very good," nodded the Inspector.

"And the height and build fit," added Holmes. "There is also the addition of a nick in the right scapula. Moriarty was stabbed there, and such a mark is consistent with this."

Lestrade nodded again and made a note on a leaf of his notebook. "Well, gentlemen - this in combination with the Doctor's testimony" - I had already examined the damage to the bones and identified the various fractures as being consistent with a fall from a great height - "is enough evidence for a positive identification to my mind. I trust neither of you have any further reason why we might delay releasing the remains to the family?"

"None at all," I said, eager to have the whole affair done with.

Holmes only shook his head, eyes still fixed darkly on the skeleton.

* * *

The funeral was announced in the paper some weeks later. I had risen later than was my habit that morning, owing to an emergency with a patient the night before, and found the newspaper already riffled through and scattered around the sitting room. The breakfast sat on the table, untouched, curls of steam rising from plates forlornly as though aware of their neglect. Holmes slouched in his armchair, eyes flat and inscrutable as slate, his old clay pipe clenched cold and unlit between his teeth.

Recognizing that I had found him in a rather uncommunicative humor, I merely heaved a sigh and busied myself by gathering up the discarded pages of the paper. I snatched a few up from beside Holmes' chair, and then the sections which were draped still folded over the arm of the settee, finally folding them all together again - though rather out of their original order - and laying them on the table. As I did, the small announcement of the Professor's burial - a scant few lines, naming the place and time and little more - caught my eye. A painful memory surfaced in my mind as I remarked the relative anonymity in which Holmes' greatest adversary would be laid to rest, while Holmes' own disappearance had caused such a stir those years before.

No flag would fly at half-mast for the Professor. No black muslin would appear, draping the buildings of the city in somber remembrance, and no policemen or grateful former clients would be seen going about in mourning dress. It had seemed, when Holmes had appeared to die, that all of London had, in some measure, grieved him.

As for Professor Moriarty, there was no more extraordinary gesture made concerning his death than the fact that, beside the announcement of his funeral in the paper, Sherlock Holmes had placed a small mark in pencil.

* * *

It was a stark, lonely patch of ground, and the polished black marble of the headstone which stood upon it did nothing to improve the fact. Rather than have his brother's remains transported to the old family plot in Ireland, Colonel James Moriarty had found it a more prudent course of action to inter them in London, quickly and quietly. He stood at the foot of the patch of raw earth that formed the newly covered grave, military posture relaxed slightly, the cold, sharp wind tugging at the hem of his overcoat.

The younger man beside him was crying.

He would have never thought to see tears from this particular fellow, not in all the years his brother had known him. And yet, his unusual, pale eyes shone with a dampness that collected at the corners and caught in his lashes, threatening to spill over.

"An astroid," he remarked with a nod towards the geometric figure inscribed above the Professor's name on the headstone, voice steady but low and somber with emotion.

The Colonel nodded. "He would have wanted it. It was the work he was most proud of." He thought for a moment, then added cautiously: "He was proud of your hand in it, too."

Sherlock Holmes' only reaction to this was a faint, bitter smile at the irony of life.


	2. The Wax Keys

250 pounds of lead shot. That had been the point upon which the whole matter had turned. I had come across just such an inconsistency in the records provided by Lestrade's informant - and known instantly that if he sent his men to Greenwich, following the tip the yard had been given, disaster would ensue. The greatest robbery of the century would have taken place on a train out of London Bridge station, and anyone who could have put a stop to it would have been miles and hours away, irretrievable and hopelessly ignorant.

250 pounds worked out to be the exact weight of the gold bars bound for france on the London Bridge train. The weight of the shipment Lestrade proposed to chase to Greenwich would have been absurd had it been anything more than sixty.

I did not explain this as we sprinted from his office, he calling out to the rest of the men on duty in the building to grab their revolvers and aid us - there was no time. I hadn't been absent from London near long enough to forget what it's traffic would be like at that hour. We had our best chance of reaching the train in time on foot.

I had hardly been home for a week at this point. I had gone to the yard that morning to wrap up the business with Adair, and the file on Lestrade's informant had caught my eye while I was waiting for him in his office. Thankfully he still trusted me enough to follow me to London Bridge station, and bring his colleagues.

We came desperately close to being too late.

The train in question was small and carried only one baggage car. I dashed onto the platform just as two of the rail line's guards were sliding the door of it shut - but I couldn't help but note, in the narrow view of the interior it afforded, a stack of strangely robust, utilitarian luggage - at least a dozen identical heavy leather satchels, ideal for carrying lead shot onto the train, and gold off of it - the corner of what must have been a heavy steel safe, and - a coffin? With a thrill of alarm, the whole scheme became clear to me in an instant. Three strides brought me to the luggage car itself, and I didn't hesitate in diving in between the two guards and getting an arm in the way of the door before it could be shut. I hissed between my teeth as the heavy wood and steel contraption slid closed on it. I would have looked incredibly mad if I hadn't had a dozen yarders on my heels to back me up. The guards, for their part, were more than a little flustered, and their first notion was to remove me from the door way of the car and ignore my demands that they open the coffin it contained. Upon the arrival of the yarders, however, and Lestrade's naming me as Mr. Sherlock Holmes, they became much more compliant.

The coffin was found to contain, not a corpse, but a perfectly live and well cracksman - none other than the infamous Robert Agar, recently paroled from a stretch in Newgate, with wax replicas of all four keys needed to open the safes on board on his person. He was quick to give up his accomplices - one of whom proved to be the guard who was to ride in the baggage car with the gold shipment, and another fellow whom we found in the last first class compartment with a rack of mountaineering gear, presumably for traversing the train to reach the baggage car, and the tools necessary to pick the lock that would have secured the door had it been allowed to leave. All in all, it was a very tidy collar. And a deuced close save.

I was standing near the edge of the platform as the whole event concluded, my part in the drama now over, watching as the yarders hauled away their catch and generally tried to restore order when Lestrade approached me. I saw that he had the four wax keys in his hand. But, this is not what suddenly arrested my attention, such that I didn't catch a word of what he spoke to me.

The ground floor of the station offices behind him were walled on this side by windows that stretched from the pavement to the stone border below those of the second floor. In one of them, over his shoulder, I could see the reflection of someone I knew.

Or had known. A ghost, now. Someone lost to me even before his death.

The familiar hooded eyes regarded me warmly, the thin mouth quirked in the faintest smile of approval. The stooped figure nodded. _"Proud of you, lad._"

"...And the boys thought you should have them," Lestrade was saying. Mechanically I held out a hand to accept the keys he offered, but was only startled from my reverie when I heard them clatter to the pavement. I confess I jumped. "Mr. Holmes?" Lestrade asked. I looked at him, then down at the keys that had slipped between my fingers. I could see my hand shaking and withdrew it quickly.

"It's nothing," I muttered in response to his obvious concern as I stooped to pick up the keys. "Got my arm closed in that bloody door." I straightened up casually, dusting the keys off. "Thank you for these, Lestrade - but I think the bank that owns those safes would rather they were destroyed." This was enough to distract him. He exclaimed something along the lines of 'of course' and assured me that he would see to it, but this for the most part was also lost on me. I glanced back to the window of the station office.

This time, it was empty. Moriarty was gone.


	3. An Epitaph

The first person Sherlock Holmes killed, he never touched. He was in his first year at university, and had never so much as laid eyes on the man. He would never have known his name, had he not read of the 'mysterious death' in the papers and recognized the elements of what had begun as a harmless intellectual exercise between he and his old mathematics tutor.

It was not to be the only crime of his career in which he could have enacted every detail that escaped the police as though his own hand had carried out the deed, but it was the first in which the felony he compounded by his silence was his own.

Confronting Moriarty with what he knew had forever drawn the line between them.

True, the Professor may have ultimately been the guilty party, and Holmes' actions may have amounted to nothing more than naively solving riddles, but seeing the stamp of his own intellect on a violent murder was something he would never forget.

He may never have touched his victim, but he still felt the blood on his hands.


	4. Convolution

It was Holmes' face, but not his mien. The cold-blooded reasoner I had known was not at the forefront of this man's personality, but lurked in his eyes at best. They studied me shrewdly from amidst expressive features, who's candor I nonetheless felt I did not like to trust. It was perhaps Holmes' ghost, haunting someone else's body.

"What are you doing here, Watson?" he asked.

The lilt in his voice was unmistakably Irish. He swiveled his head to the side to regard me obliquely as he spoke, in a manner that would be described as reptilian at worst and avian at best.

"I have more reason to ask that of you," I said levelly.

The ghost gestured with the hat in his hand to the headstone we stood before, an incredulous little smile twisting the corner of his mouth without humor. "This is Sebastian Moran's grave," he rejoined.

I replied, voice flat and cold as ice to my own ears, "You're dead."

"So I am." The smile faded.

"Then you will answer first."

Not-Holmes sighed, settling the hat over his wind-tousled dark hair and slipping his hands into his overcoat pockets. He looked down at the grave, once animated features now inscrutable. "You visited my grave, once."

I shook my head. "I visited both of them once I learned the truth."

"Then," he replied, "you understand."

"Moran was your friend."

He hesitated in a manner that was infuriatingly Holmsian, then answered with a frankness which was not. "Yes."

"And I killed him," I owned without remorse.

"No," said my companion, "a jury killed him. He would never have appeared before them, were it not for your involvement – but the Adair business was foolishness on his part, and he ought to have known it. I am the one person who could have prevented it all, so that is where the blame lies."

"Holmes -" I began to protest, habit already having formed some reassurance against this familiar sort of self-recrimination on my lips, but was cut off by the piercing, grey-eyed look I was suddenly fixed with for this as much as by realizing my error.

The man who was not Holmes all but gaped at me in surprise for a moment before breaking into a grim smile I had never seen before on his countenance and chuckling wryly.

"Oh, Watson," he said. "Good old Watson." The smile was exchanged for a frown and he sobered before adding: "I owe you a thousand apologies."

"I imagine you owe many people restitution for the wrongs you have done them," I said, manner cooling once again, "but in this instance Sebastian Moran is not one of them, and we both know it."

"I abandoned him as surely as I did you when I disappeared," Not-Holmes returned dismally, shaking his head. "I never expected to pay for it."

"Pay?" I exclaimed - shocked, perhaps in light of my own losses, at such self-pity. "You are not the one in the grave."

I had spoken almost without thinking, and was surprised to see the effect of my words. The face of the man beside me darkened suddenly before the aloof mask I had once been so accustomed to addressing over breakfast or across a train compartment descended upon it. He seemed more like Holmes than ever when he turned to me and replied: "You're right, of course. I suppose it has cost me the least, out of all of us. I suppose you have been paying for it as well."

It was difficult to think of how to answer. "I have...grieved, yes. You were – Sherlock Holmes was my friend. My dearest friend." I waved a hand towards the grave. "You understand."

"He was a lie, Watson," my companion said with a gentleness that seemed out of character for both the man I had known and his arch enemy.

"You still look like him," I accused.

"But I am not him."

"Parts of you are. Parts of him were charade, perhaps – but even you could not keep up a total lie for so long. You had to allow bits of truth in."

"You can't even think of what name to call me by," he argued, as though to point out to me the disorder in my own thoughts.

"Exactly so," I nodded. "You remind me too much of him. Part of me is still convinced that James Moriarty murdered him, so I should prefer not to address you as professor either, if you don't mind."

"I don't," the man all but scoffed. "As a title it only serves to remind me of a degree of success I failed to attain."

"I assume you refer to the chair of mathematics you were dismissed from."

"Indeed." He looked at me sidelong again, Holmes in his eyes and Moriarty in his manner. "I suppose you imagine that my dismissal was the result of some gruesome scandal – that some infraction of mine had been uncovered?"

I blinked in astonishment – Holmes had once been accustomed to use the words 'some infraction of mine' to refer to incidents such as setting fire to the drapes or breaking Mrs. Hudson's china – then nodded.

The alien smile flashed across Not-Holmes' features again. "Well, no victim came forward, and no one in my employ betrayed me. It was discovered that my credentials had been falsified. Can you imagine? So great a setback, all over the matter of a simple forgery. My work should have spoken for itself – it was the truest thing I have ever done – but, alas, my origins were found to be too humble, and, what was more, I had embarrassed the venerated academics whose ranks I sought to enter by my deception. That was what cost me the chair."

I stared at the grave for some time, thinking about this and saying nothing, before my companion finally observed: "You're wondering why I'm willing to tell you this."

"You never spoke very freely about your past before," I acknowledged.

He shrugged. "I had quite a bit more to hide, then." He dug a toe briefly into the rain-softened sod at our feet before adding: "And if I were to repay you with anything, I think you would want the truth."

I continued to study the headstone, answering quietly without looking up. "What if I wish to know no more of it?"

The man beside me said nothing for a moment, until I observed his posture shift slightly in my peripheral vision. "Then if I can do nothing more for you," he said, voice even as slate, "I will take my leave."

He turned on his heel to go.

* * *

_A/N: I use 'Convolution' in the title in the mathematical sense._


End file.
